Catheter system and methods of medical uses of same, including diagnostic and treatment uses for the heart

ABSTRACT

The present invention includes systems, devices and methods for treating and/or diagnosing a heart arrhythmia, such as atrial fibrillation. Specifically, the present invention provides a system including a diagnostic catheter and an ablation catheter. The diagnostic catheter includes a shaft, multiple dipole mapping electrodes and multiple ultrasound transducers. The ablation catheter is slidingly received by the diagnostic catheter shaft.

RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 14/422,941, filed Feb. 20, 2015, which is a 371national stage application of Patent Cooperation Treaty Application No.PCT/US2013/057579 filed Aug. 30, 2013, entitled CATHETER SYSTEM ANDMETHODS OF MEDICAL USES OF SAME, INCLUDING DIAGNOSTIC AND TREATMENT USESFOR THE HEART, which in turn claims priority under 35 USC 119(e) fromU.S. Provisional Patent Application 61/695,535 filed Aug. 31, 2012,entitled SYSTEM AND METHOD FOR DIAGNOSING AND TREATING HEART TISSUE, thecontents of which are incorporated herein by reference in theirentirety.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 13/858,715, entitled Method andDevice for Determining and Presenting Surface Charge and DipoleDensities on Cardiac Walls, filed Apr. 8, 2013, which is a continuationof U.S. patent application Ser. No. 12/376,270, entitled Method andDevice for Determining and Presenting Surface Charge and DipoleDensities on Cardiac Walls, filed Feb. 3, 2009, published asUS2009264781, which was a 35 USC 371 national stage filing of PCTApplication No. CH2007/000380, entitled Method and Device forDetermining and Presenting Surface Charge and Dipole Densities onCardiac Walls, filed Aug. 3, 2007, published as WO 2008/014629, whichclaimed priority to Swiss Patent Application No. 1251/06 filed Aug. 3,2006, each of which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 13/946,712, entitled A Device andMethod for the Geometric Determination of Electrical Dipole Densities onthe Cardiac Wall, filed Jul. 19, 2013, which is a continuation of U.S.patent application Ser. No. 12/863,411, entitled A Device and Method forthe Geometric Determination of Electrical Dipole Densities on theCardiac Wall, filed Jul. 16, 2010, published as US20100298690, which wasa 35 USC 371 a national stage application of Patent Cooperation TreatyApplication No. PCT/IB09/00071 filed Jan. 16, 2009, entitled A Deviceand Method for the Geometric Determination of Electrical DipoleDensities on the Cardiac Wall, published as WO 2009/090547, whichclaimed priority to Swiss Patent Application 00068/08 filed Jan. 17,2008, each of which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto Applicant's co-pending international application, Serial NumberPCT/US2012/028593, entitled Device and Method for the GeometricDetermination of Electrical Dipole Densities on the Cardiac Wall, theentirety of which is incorporated herein.

FIELD OF INVENTION

The invention relates to the field of medical devices used inelectrophysiology, and more particularly to the field of devices formapping activity of internal organs, catheters for treating same, andmethods for using such devices and catheters.

BACKGROUND

The use of electrodes within a body for measuring certain electricalcharacteristics of the heart is routinely performed, sometimes referredto as cardiac mapping. And the use of ablation catheters to selectivelyablate nerves or tissue, for example, within the body is also routinelyperformed. Cardiac mapping and ablation are performed separately, usingdifferent, specialized devices or systems.

An ablation catheter can be used, for example, in a medical procedure totreat some types of arrhythmias, which are problems with the rate orrhythm of the heartbeat. An ablation catheter is a long, thin, flexibletube that is put into a blood vessel in the arm, groin (upper thigh), orneck of the patient and guided into the heart through the blood vessel.In catheter ablation, radiofrequency (RF) energy is usually used toproduce heat from radiofrequency energy that selectively destroys theheart tissue.

For cardiac mapping, as an example, currently electrodes can belocalized within the body either by a permanent magnetic field, amagnetic field generated by electromagnets, or an impedance measurement.

The Carto 3 System by Biosense Webster, Inc. is an example of anelectromagnetic field measurement system, in accordance with the priorart. Such a system needs specialized electrodes with electromagneticcoils.

The Localisa® Intracardiac Navigation System by Medtronic, Inc. is anexample of an impedance measurement system, in accordance with the priorart. (Localisa is registered as a United States trademark by MedtronicInc.) Such a system can be inaccurate due to tissue anisotropy andrespiration.

SUMMARY

Provided is an ablation system comprising a diagnostic catheter and anablation catheter. The diagnostic catheter is configured to providedipole mapping information as well as to slidingly receive the ablationcatheter. The system is configured to provide anatomical mappinginformation, as well as to identify the location of (“localize”)electrodes within and/or upon the human body by delivering and recordingelectric signals between them. In accordance with various aspects of thepresent invention, a single conduit can provide left atrial access andmaneuvering within the atrium to map and/or ablate cardiac tissue,avoiding the need to perform a double transseptal puncture. Localizationof electrodes enables visualization and precise maneuvering of one ormore catheters of the system. Navigation of the one or more catheterscan be performed based on the localization information.

In accordance with one aspect of the present disclosure, an ablationsystem comprises an ablation catheter and a diagnostic catheter. Theablation catheter comprises an elongate shaft with a distal portion andat least one ablation element positioned on the ablation catheter shaftdistal portion and configured to delivery energy to tissue. Thediagnostic catheter comprises an elongate shaft comprising a distal endwhere the diagnostic catheter shaft is configured to slidingly receivethe distal portion of the ablation catheter shaft; an expandableassembly mounted to the diagnostic catheter shaft and configured totransition from a compacted state to an expanded state; a plurality ofdipole mapping electrodes coupled to the expandable assembly; and aplurality of ultrasound transducers coupled to the expandable assembly.The ablation catheter may be used to treat a patient, for example, hearttissue of a patient.

The system can be configured to treat at least one of an atrialfibrillation patient or a ventricular tachycardia patient.

The system can be configured to treat at least one of the left atrium ofthe patient or the left ventricle of the patient, while utilizing asingle transseptal puncture.

The system can be configured to treat the left ventricle of the patient,while utilizing a single crossing of the aortic valve to access the leftventricle.

The diagnostic catheter can be configured to provide informationselected from the group consisting of: surface unipolar voltageinformation; surface bipolar voltage information; surface charge densityinformation; monophasic action potential information; anatomicalgeometry information such as heart wall position and heart wallthickness information; and combinations of these. In some embodiments,the system further comprises a memory storage module comprising criteriainformation, and the information provided by the diagnostic catheter canbe compared to the stored criteria information.

The diagnostic catheter can be configured to be positioned in at leastone of the left atrium or the left ventricle.

The diagnostic catheter can comprise a distal portion and a steeringassembly, and the steering assembly can be configured to steer thediagnostic catheter distal portion in one or more directions. In someembodiments, the steering assembly comprises a robotic steeringassembly.

The diagnostic catheter can comprise a distal portion with a diameterless than or equal to 15 Fr.

The diagnostic catheter shaft can be configured to slidingly receive thedistal portion of the ablation catheter and the distal portion of anadditional elongate device. The additional elongate device can comprisea catheter selected from the group consisting of: a diagnostic cathetersuch as a diagnostic catheter constructed and arranged to record signalsfrom the left atrium, the left ventricle, the right atrium, the Bundleof HIS, the right ventricular apex, a pulmonary vein or the coronarysinus; a catheter with a linear array of electrodes; a catheter with ahelical array of electrodes; a pacing catheter; an energy deliverycatheter such as a catheter constructed and arranged to deliverradiofrequency energy, cryogenic energy, laser energy or ultrasoundenergy; and combinations of these.

The expandable assembly can be positioned on the distal end of thediagnostic catheter shaft.

The expandable assembly can be configured to radially expand. In someembodiments, the system further comprises a sheath with a distal end,and the expandable assembly can be configured to radially expand as itexits the sheath distal end.

The expandable assembly can comprise a plurality of expandable members.The plurality of expandable members can be formed of a materialcomprising a shape memory alloy, for example a shape memory alloycomprising Nitinol. The plurality of expandable members can be formed ofa material comprising a shape memory polymer, for example a shape memorypolymer comprising a triple shape acrylic.

The expandable assembly can comprise a plurality of bendable splines,where each spline comprises a proximal end and a distal end. Each splinecan further comprise a set of spaced dipole mapping electrodes. The setof spaced dipole mapping electrodes can comprise at least 4 dipolemapping electrodes, or at least 6 dipole mapping electrodes, or at least8 dipole mapping electrodes. Each spline can further comprise a set ofspaced ultrasound transducers. The set of spaced ultrasound transducerscan comprise at least 4 ultrasound transducers, or at least 6 ultrasoundtransducers, or at least 8 ultrasound transducers. Each spline canfurther comprise at least two of the plurality of dipole mappingelectrodes and at least two of the plurality of ultrasound transducers.For example, one or more of the plurality dipole mapping electrodes canbe disposed between two adjacent ultrasound transducers on each spline.

Each spline proximal end can be fixedly attached at a location proximatethe diagnostic catheter elongate shaft distal end, and each splinedistal end can be connected in a circumferential arrangement. Thecircumferential arrangement can define an opening when the expandableassembly is in an expanded state. The diagnostic catheter shaft cancomprise a distal portion defining a central axis, and the opening canbe relatively centered about the axis. The ablation catheter cancomprise a distal end, and the opening can be positioned such thatadvancement of the ablation catheter through the diagnostic cathetercauses the ablation catheter shaft distal end to tend to pass throughthe opening. The expandable assembly can further comprise two or moreguide elements, for example two or more guide elements that can beconfigured such that during advancement of the ablation catheter throughthe diagnostic catheter, the ablation catheter distal end is directed bythe guide elements to pass through the opening. The two or more guideelements can be configured to partially advance from the diagnosticcatheter distal end as the diagnostic catheter transitions from itscompacted state to its expanded state. The expandable assembly canfurther comprise a guide tube connected to the opening, for example theguide tube can be configured to partially advance from the diagnosticcatheter distal end as the diagnostic catheter transitions from itscompacted state to its expanded state.

The ablation catheter can comprise a distal end, and each spline canfurther comprise a mid portion positioned between its proximal end andits distal end, and the ablation catheter distal end can be configuredto be radially deflected to cause the ablation catheter distal end topass between a first spline mid portion and a second spline mid portionwhen the bendable splines are in an expanded state. The expandableassembly can further comprise two or more guide elements, for examplewhere the deflection of the ablation catheter distal end further cancause the ablation catheter distal end to pass between two guideelements.

The plurality of dipole mapping electrodes can comprise non-polarizingmetals. The plurality of dipole mapping electrodes can comprisenon-noble metals constructed and arranged to oxidize when in contactwith at least one of blood, blood plasma, or saline solutions. Theplurality of dipole mapping electrodes can comprise a coating selectedfrom the group consisting of: a metal oxide coating; a conductivepolymer coating; and combinations of these. The plurality of dipolemapping electrodes can comprise a coating constructed to be at least oneof electrochemically catalytic or directly reactive with at least one ofblood, blood plasma or saline solutions. The plurality of dipole mappingelectrodes can further comprise an outer layer, an inner layerpositioned within the outer layer, where the outer layer can comprise animpedance lowering layer and the inner layer can be configured to bondto the outer layer. The plurality of dipole mapping electrodes cancomprise a polarizing metal. The plurality of dipole mapping electrodescan comprise a noble metal.

The plurality of dipole mapping electrodes can comprise a quantity equalto the quantity of the plurality of ultrasound transducers. A number ofdipole mapping electrodes can be greater than a number of ultrasoundtransducers. Each of the plurality of dipole mapping electrodes can bedisposed between two ultrasound transducers. Each of the plurality ofultrasound transducers can be disposed between two dipole mappingelectrodes.

The plurality of dipole mapping electrodes can comprise at least onedipole mapping electrode with an impedance of less than 10,000 ohms forfrequencies above 0.1 hertz.

The plurality of ultrasound transducer can comprise an assembly selectedfrom the group consisting of: single or multi-element piezoelectricceramics; piezoelectric micro-machined ultrasound transducers (pMUT);capacitive micro-machined ultrasound transducers (cMUT); piezoelectricpolymers; and combinations of these.

The diagnostic catheter shaft can comprise a braided layer. The braidedlayer can comprise two or more electrical conductors positioned therein.The two or more electrical conductors can comprise two or more coaxialcables. At least one conductor can be electrically connected to a dipolemapping electrode, and at least one conductor can be electricallyconnected to an ultrasound transducer. At least one conductor can bepositioned in the braided layer in a helical pattern.

The ablation catheter can comprise a distal end, and the at least oneablation element can be positioned on the ablation catheter distal end.The at least one ablation element can comprise multiple electrodespositioned in a linear array on the ablation catheter shaft distalportion. The ablation catheter can comprise multiple electrodesconfigured to deliver energy and record electrical signals. The ablationcatheter can comprise multiple electrodes configured to deliver energyand record dipole mapping information.

The ablation catheter can comprise a steering mechanism configured toselectively maneuver the distal portion of the ablation catheter. Thesteering mechanism can comprise an anchoring element and one or moreattached pull wires configured to enable uni-directional tomulti-directional displacement of the ablation catheter distal portion.The steering mechanism can comprise a robotic steering mechanism.

The at least one ablation element can comprise at least one electrode.The at least one ablation element can comprise an ablation elementselected from the group consisting of: electrode; vessel configured todeliver cryogenic energy; laser diode; optical fiber configured todeliver ablative energy; microwave energy delivery element; ultrasoundenergy delivery element; drug or other agent delivery element; andcombinations of these. The at least one ablation element can beconfigured to deliver an energy form selected from the group consistingof: radiofrequency energy; cryogenic energy; laser energy; light energy;microwave energy; ultrasound energy; chemical energy; and combinationsof these.

The system can further comprise a distance measurement assembly. Thedistance measurement assembly can produce a set of data representing thedistance between each ultrasound transducer of the plurality ofultrasound transducers and a tissue surface orthogonal to eachultrasound transducer. The distance measurement assembly can beconfigured to deliver a signal to the diagnostic catheter plurality ofultrasound transducers, record a first generated signal from thediagnostic catheter plurality of ultrasound transducers, and produce afirst set of distance information based on the recording of the firstgenerated signal. The ablation catheter can comprise at least oneultrasound transducer, and the distance measurement assembly can beconfigured to deliver a signal to the ablation catheter at least oneultrasound transducer, record a second generated signal from theablation catheter at least one ultrasound transducer, and produce asecond set of distance information based on the recording of the secondgenerated signal. In some embodiments, the system further comprises anaccessory device comprising at least one ultrasound transducer, and thedistance measurement assembly can be configured to deliver a signal tothe accessory device at least one ultrasound transducer, record a secondgenerated signal from the accessory device at least one ultrasoundtransducer, and produce a second set of distance information based onthe recording of the second generated signal. The accessory device cancomprise a device selected from the group consisting of: externalultrasound device; transesophageal echocardiography device; intracardiacechocardiography device; a catheter with a linear array of recordingelectrodes; a catheter with a helical array of recording electrodes;coronary sinus diagnostic catheter recording device; and combinations ofthese.

The system can comprise at least a first electrode and a secondelectrode and, the distance measurement assembly can produce datarepresenting the distance between the first electrode and the secondelectrode. The first electrode can be configured to deliver anelectrical signal, and the second electrode is configured to record theelectrical signal delivered by the first electrode, and the distancemeasurement assembly can produce the data based on the recordedelectrical signal. The delivered signal can comprise an electriccurrent. The recorded signal can comprise a voltage. The distancemeasurement assembly can be configured to produce the first set ofdistance information based on a comparison of the first generated signalto the delivered signal. The first set of distance information can berepresented by electrical impedance. The first set of distanceinformation can be based on a physiologic impedance determined usingknown distances between the first electrode and the second electrode. Insome embodiments, the expandable assembly can comprise at least onespline, and the first electrode and the second electrode can be attachedto the at least one spline. The first set of distance information can bedetermined using an impedance value for circulating blood and/or tissueproximate at least the first and second electrodes.

The first electrode and the second electrode can comprise dipole mappingelectrodes. The expandable assembly can comprise a first splinecomprising the first electrode and a second spline comprising the secondelectrode, and the distance measurement assembly can produce datarepresenting the distance between the first spline and the secondspline. The first electrode can comprise a dipole mapping electrode, andthe ablation catheter can comprise the second electrode, and thedistance measurement assembly can produce data representing a distancebetween the diagnostic catheter and the ablation catheter. In someembodiments, the system can further comprise a third catheter devicecomprising the second electrode, and the first electrode can comprise adipole mapping electrode, and the distance measurement assembly canproduce data representing a distance between the diagnostic catheter andthe third catheter device.

The diagnostic catheter can comprise at least two electrodes, and thedistance measurement assembly can be configured to deliver a signal tothe diagnostic catheter at least two electrodes, record a firstgenerated signal from the diagnostic catheter at least two electrodes,and produce a first set of distance information based on the recordingof the first generated signal. The diagnostic catheter plurality ofdipole mapping electrodes can comprise the at least two electrodes. Thefirst set of distance information can represent the geometricconfiguration of the expandable assembly.

The system can further comprise a second diagnostic catheter comprisingat least one electrode, and the distance measurement assembly can befurther configured to deliver a signal to the second diagnostic catheterat least one electrode, record a second generated signal from the seconddiagnostic catheter at least one electrode, and produce a second set ofdistance information based on the recording of the second generatedsignal.

The ablation catheter can comprise at least one electrode, and thedistance measurement assembly can be further configured to deliver asignal to the ablation catheter at least one electrode, record a secondgenerated signal, and produce a second set of distance information basedon a comparison of the signal delivered to the ablation catheter atleast one electrode and the recording of the second generated signal.The diagnostic catheter can comprise an electrode and the second set ofdistance information can comprise the distance between the ablationcatheter at least one electrode and the diagnostic catheter electrode.The ablation catheter at least one electrode can comprise a firstelectrode and a second electrode, and the distance information cancomprise the distance between the first electrode and the secondelectrode.

The system can further comprise a second ablation catheter comprising atleast one electrode, and the distance measurement assembly can befurther configured to deliver a signal to the second ablation catheterat least one electrode, record a second generated signal from the secondablation catheter at least electrode, and produce a second set ofdistance information based on the recording of the second generatedsignal.

The system can further comprise a second diagnostic catheter comprisingat least one electrode, and the distance measurement assembly can befurther configured to deliver a signal to the second diagnostic catheterat least one electrode, record a second generated signal from the seconddiagnostic catheter at least electrode, and produce a second set ofdistance information based on the recording of the second generatedsignal.

The system can further comprise at least one body surface electrode, andthe distance measurement assembly can be further configured to deliver asignal to the at least one body surface electrode, record a secondgenerated signal from the at least one body surface electrode, andproduce a second set of distance information based on the recording ofthe second generated signal.

The system can further comprise a steerable sheath comprising anelongate shaft with a proximal end, a distal end, and a lumentherethrough, where the sheath elongate shaft can be configured to beinserted into a body and the sheath lumen can be configured to slidinglyreceive the diagnostic catheter shaft.

The system can further comprise a robotically manipulatable assembly.The system can further comprise a robotic assembly configured tomanipulate the robotically manipulatable assembly. The system can beconfigured to manipulate the robotically manipulatable assembly based onan analysis of at least one of: dipole mapping information recorded byat least one dipole mapping electrode or distance information recordedby at least one ultrasound transducer. The system can be configured tomanipulate the robotically manipulatable assembly based on an analysisof dipole mapping information recorded by at least one dipole mappingelectrode and distance information recorded by at least one ultrasoundtransducer. The system can comprise a first electrode and a secondelectrode, and the system can be further configured to manipulate therobotically manipulatable assembly based on distance informationproduced by comparing a signal delivered to the first electrode to asignal recorded by the second electrode. The system can be configured toautomatically manipulate the robotically manipulatable assembly, forexample, the system can be configured to receive manipulation criteriafrom an operator, and the automatic manipulation can be performed basedon the operator input information. The system can be configured toassess contact with tissue, and the robotically manipulatable assemblycan be manipulated based on the contact assessment, for example thesystem can be configured to receive contact threshold criteria from anoperator, and the manipulation can be performed based on the operatorinput information. The system can be configured to allow an operator tomanipulate the robotically manipulatable assembly. The ablation cathetercan comprise the robotically manipulatable assembly, for example wherethe ablation catheter comprises a steerable portion that is configuredto be robotically manipulated. The diagnostic catheter can comprise therobotically manipulatable assembly, for example where the diagnosticcatheter comprises a steerable portion that is configured to berobotically manipulated.

The system can further comprise an energy source configured to provideenergy to the at least one ablation element of the ablation catheter.The energy source can be configured to provide an energy form selectedfrom the group consisting of: radiofrequency energy; cryogenic energy;laser energy; light energy; microwave energy; ultrasound energy;chemical energy; and combinations of these. The diagnostic catheter cancomprise at least one ablation element and the energy source can beconfigured to deliver energy to the diagnostic catheter at least oneablation element. The system can further comprise a second ablationcatheter comprising at least one ablation element, and the energy sourcecan be configured to deliver energy to the second ablation catheter atleast one ablation element.

The system can further comprise an electrical signal source coupled tothe plurality of dipole mapping electrodes. The electrical signal sourcecan comprise a current source.

The system can further comprise an electrogram recording catheter. Thediagnostic catheter can be configured to be positioned in the leftatrium, and the electrogram recording catheter can be configured to bepositioned in the coronary sinus. The electrogram recording catheter cancomprise a catheter with a helical array of electrodes. The electrogramrecording catheter can be configured to be positioned in at least one ofthe left atrium; a pulmonary vein; or the coronary sinus. Theelectrogram recording catheter can comprise a distal portion configuredto be slidingly received by the diagnostic catheter shaft.

The system can further comprise a second ablation catheter. The secondablation catheter can be configured to be slidingly received by thediagnostic catheter shaft. The second ablation catheter can be ofsimilar or dissimilar construction as the first ablation catheter.

The system can further comprise a third catheter device configured to beslidingly received by the diagnostic catheter shaft. The third catheterdevice can comprise a device selected from the group consisting of: acatheter with helical array of electrodes such as a lasso catheter; apacing catheter; an energy delivery catheter such as a catheterconstructed and arranged to deliver radiofrequency energy, microwaveenergy, cryogenic energy, laser energy and/or ultrasound energy; a drugor other agent delivery catheter such as a catheter constructed andarranged to deliver antiarrhythmic medications, stem cells, or otherbiologic agents; a mechanical device delivery catheter; and combinationsof these. The third catheter device can comprises a mechanical devicedeployment catheter. The mechanical device deployment catheter can beconfigured to deploy a device selected from the group consisting of;robotic navigation or manipulation device, an atrial appendage closuredevice, a valve replacement device, a tissue biopsy device; andcombinations of these. The third catheter device can comprise arobotically manipulatable catheter device.

The system can further comprise a treatment device. The treatment devicecan comprise a distal portion configured to be slidingly received by theshaft of the diagnostic catheter. The treatment device can comprise adevice selected from the group consisting of: a pacing device; adefibrillation device; a stent delivery device; a drug delivery device,a stem cell delivery device; and combinations of these.

In accordance with another aspect of the present disclosure, adiagnostic catheter comprises an elongate shaft comprising a distal end,where the shaft is configured to slidingly receive the distal portion ofthe shaft of a second catheter; an expandable assembly mounted to thediagnostic catheter shaft and configured to transition from a compactedstate to an expanded state; a plurality of dipole mapping electrodescoupled to the expandable assembly; and a plurality of ultrasoundtransducers coupled to the expandable assembly.

The catheter can be configured to provide information selected from thegroup consisting of: surface unipolar voltage information; surfacebipolar voltage information; surface charge density information;monophasic action potential information; anatomical geometryconfiguration; and combinations of these.

The catheter can be configured to be positioned in at least one of theleft atrium and the left ventricle.

The catheter can further comprise a robotically manipulatable assembly.The catheter can comprise a steerable portion configured to berobotically manipulated. The catheter can comprise a shaft configured tobe robotically at least one of advanced or retracted.

The expandable assembly can be positioned on the distal end of theshaft. The expandable assembly can be configured to radially expand. Insome embodiments, the catheter further comprises a sheath with a distalend, and the expandable assembly can be configured to radially expand asit exits the sheath distal end.

The expandable assembly can comprise a plurality of expandable members.The plurality of expandable members can be formed of a materialcomprising a shape memory alloy, for example a shape memory alloycomprising Nitinol. The plurality of expandable members can be formed ofa material comprising a shape memory polymer, for example a shape memorypolymer comprising a triple shape acrylic.

The expandable assembly can comprise a plurality of bendable splines,where each spline comprises a proximal end and a distal end. Each splinecan further comprise a set of spaced dipole mapping electrodes. The setof spaced dipole mapping electrodes can comprise at least 4 dipolemapping electrodes, or at least 6 dipole mapping electrodes, or at least8 dipole mapping electrodes. Each spline can further comprise a set ofspaced ultrasound transducers. The set of spaced ultrasound transducerscan comprise at least 4 ultrasound transducers, or at least 6 ultrasoundtransducers, or at least 8 ultrasound transducers. Each spline canfurther comprise at least two of the plurality of dipole mappingelectrodes and at least two of the plurality of ultrasound transducers.For example, one or more of the plurality dipole mapping electrodes canbe disposed between two adjacent ultrasound transducers on each spline.

Each spline proximal end can be fixedly attached at a location proximatethe diagnostic catheter elongate shaft distal end, and each splinedistal end can be connected in a circumferential arrangement. Thecircumferential arrangement can define an opening when the expandableassembly is in an expanded state. The diagnostic catheter shaft cancomprise a distal portion defining a central axis, and the opening canbe relatively centered about the axis. The expandable assembly canfurther comprise two or more guide elements, for example two or moreguide elements configured to cause a distal end of a second shaft totend to pass through the opening.

The plurality of dipole mapping electrodes can comprise non-polarizingmetals. The plurality of dipole mapping electrodes can comprisenon-noble metals constructed and arranged to oxidize when in contactwith at least one of blood, blood plasma, or saline solutions. Theplurality of dipole mapping electrodes can comprise a coating selectedfrom the group consisting of: a metal oxide coating; a conductivepolymer coating; and combinations of these. The plurality of dipolemapping electrodes can comprise a coating constructed to be at least oneof electrochemically catalytic or directly reactive with at least one ofblood, blood plasma or saline solutions. The plurality of dipole mappingelectrodes can further comprise an outer layer, an inner layerpositioned within the outer layer, where the outer layer can comprise animpedance lowering layer and the inner layer can be configured to bondto the outer layer. The plurality of dipole mapping electrodes cancomprise a polarizing metal. The plurality of dipole mapping electrodescan comprise a noble metal.

The plurality of dipole mapping electrodes can comprise a quantity equalto the quantity of the plurality of ultrasound transducers. A number ofdipole mapping electrodes can be greater than a number of ultrasoundtransducers. Each of the plurality of dipole mapping electrodes can bedisposed between two ultrasound transducers. Each of the plurality ofultrasound transducers can be disposed between two dipole mappingelectrodes.

The plurality of ultrasound transducers can comprise an assemblyselected from the group consisting of: single or multi-elementpiezoelectric ceramics; piezoelectric micro-machined ultrasoundtransducers (pMUT); capacitive micro-machined ultrasound transducers(cMUT); piezoelectric polymers; and combinations of these.

The diagnostic catheter shaft can comprise a braided layer. The braidedlayer can comprise two or more electrical conductors positioned therein.The two or more electrical conductors can comprise two or more coaxialcables. At least one conductor can be electrically connected to a dipolemapping electrode, and at least one conductor can be electricallyconnected to an ultrasound transducer. At least one conductor can bepositioned in the braided layer in a helical pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more apparent in view of the attacheddrawings and accompanying detailed description. The embodiments depictedtherein are provided by way of example, not by way of limitation,wherein like reference numerals refer to the same or similar elements.The drawings are not necessarily to scale, emphasis instead being placedupon illustrating aspects of the invention. In the drawings:

FIG. 1A is a perspective view of a system for treating a patientincluding an ablation catheter slidingly received by the shaft of adiagnostic catheter, in accordance with aspects of the presentinvention.

FIG. 1B is a perspective view of the system of FIG. 1A, where theablation catheter is steered into a bent configuration, in accordancewith aspects of the present invention.

FIG. 2 is a perspective view of the system of FIGS. 1A and 1B, withoutthe ablation catheter and including a push rod, in accordance withaspects of the present invention;

FIG. 2A is a magnified view of a portion of a spline of the diagnosticcatheter of FIG. 2, including one ultrasound transducer and two adjacentelectrodes, in accordance with aspects of the present invention.

FIG. 2B is a side view of the portion of the spline of FIG. 2A disposedin a body, in accordance with aspects of the present invention.

FIG. 3 is a side view of the system of FIG. 1A where the diagnosticcatheter is retracted into a sheath, in accordance with aspects of thepresent invention.

FIG. 4 is a flow chart of a method for mapping a 3-D space within a bodyusing the system, according to aspects of the present invention.

FIG. 5 is a flow chart of a method for localizing an ablation catheterwithin a body, using a 3-D mapping method such as that in FIG. 4, inaccordance with aspects of the present invention.

FIG. 6 is a schematic of an embodiment of a mapping and ablating system,in accordance with aspects of the present invention.

FIG. 7A is a perspective view of a diagnostic catheter, including guideelements, in accordance with aspects of the present invention.

FIG. 7B is a perspective view of the diagnostic catheter of FIG. 7A,including an ablation catheter that is steered outside of the guideelements, in accordance with aspects of the present invention.

DETAILED DESCRIPTION

Various exemplary embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which some exemplaryembodiments are shown. The present inventive concept may, however, beembodied in many different forms and should not be construed as limitedto the exemplary embodiments set forth herein.

It will be understood that, although the terms first, second, etc. areused herein to describe various elements, these elements should not belimited by these terms. These terms are used to distinguish one elementfrom another, but not to imply a required sequence of elements. Forexample, a first element can be termed a second element, and, similarly,a second element can be termed a first element, without departing fromthe scope of the present invention. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

It will be understood that when an element is referred to as being “on”or “attached”, “connected” or “coupled” to another element, it can bedirectly on or connected or coupled to the other element or interveningelements can be present. In contrast, when an element is referred to asbeing “directly on” or “directly connected” or “directly coupled” toanother element, there are no intervening elements present. Other wordsused to describe the relationship between elements should be interpretedin a like fashion (e.g., “between” versus “directly between,” “adjacent”versus “directly adjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used herein, specifythe presence of stated features, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, steps, operations, elements, components, and/or groupsthereof.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like may be used to describe an element and/or feature'srelationship to another element(s) and/or feature(s) as, for example,illustrated in the figures. It will be understood that the spatiallyrelative terms are intended to encompass different orientations of thedevice in use and/or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” and/or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.The device can be otherwise oriented (e.g., rotated 90 degrees or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly.

Exemplary embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized exemplary embodiments (and intermediate structures). As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments should not be construed as limitedto the particular shapes of regions illustrated herein but are toinclude deviations in shapes that result, for example, frommanufacturing.

The catheters and other devices of the present invention can includenumerous forms of diagnostic catheters such as catheters including oneor more electrodes, or therapeutic catheters such as tissue ablationcatheters. Catheters can be introduced percutaneously into a patient'sheart, such as to record electrical activity, measure distances betweenstructures, or deliver energy. External devices and systems can beincluded, such as body surface electrodes used to record electricalactivity or deliver an electric signal, or visualization devices such asexternal ultrasound or fluoroscopic imaging systems. Any of thesecatheters or other devices can include one or more electrodes and/or oneor more ultrasound transducers. The electrodes and/or ultrasoundtransducers of the present invention can be positioned at any locationon the device, for example at a distal or proximal portion of thedevice, and can be positioned internal or external to a patient's body.

Any or all of the ultrasound transducers of the present invention can beused to measure a distance between the transducer and a surface, as isknown in the art. One example includes measuring the distance betweenthe ultrasound transducer and a wall of the cardiac chamber.

Any or all of the electrodes of the present invention can be used torecord electric “signals” (e.g. voltages and/or currents) at or betweenthe electrode locations. Recorded electric signals can be used to mapelectrical activity of tissue, such as when the electrode is in contactwith tissue, and algorithms are used to correlate a recorded signal atone location that, for example, is not in contact with tissue, to asignal present at another location that, for example, is in contact withtissue. The mapped electrical activity can be further processed (e.g. interms of sources of charge and charge density and correlated withvarious physiologic parameters related to the function of the heart) andthe mapped electrical activity and other recorded and calculatedinformation can be provided visually to one or more operators of thesystem of the present invention.

Any or all of the electrodes of the present invention can be used todeliver and/or record electric signals that are generated by the system.Such delivered signals can be emitted from any one or more electrodes,and can be delivered between any two or more electrodes. Recordedsignals can comprise a signal present at a single electrode location orat multiple electrode locations (e.g. a signal representing a comparisonof two or more signals present at two or more electrode locations).Recorded signals can be measured, for example, synchronously orasynchronously in terms of voltage and/or current. Recorded signals canbe further processed in terms of, for example, resistive and reactivecomponents of impedance and/or the combined magnitude of impedance withany original or processed signal “values” (e.g. those represented by aparameter selected from the group consisting of: instantaneousamplitude; phase; peak; Root-Mean-Square; demodulated magnitude; andcombinations of these).

The terms “map” and “mapping” shall include “electrical map”,“electrical mapping”, “anatomical map”, “anatomical mapping”, “devicemap” and “device mapping”, each of which is defined herebelow.

The terms “electrical map” and “electrical mapping” shall includerecording, processing and/or displaying electrical information, such aselectrical information recorded by one or more electrodes of the presentinvention. This electrical information includes but is not limited to:cardiac or other tissue voltage measurements; cardiac or other tissuebipolar and/or unipolar electrograms; cardiac or other tissue surfacecharge data; cardiac or other tissue dipole density data; cardiac orother tissue monophasic action potentials; and combinations of these.

The terms “anatomical map” and “anatomical mapping” shall includerecording, processing and/or displaying anatomical information, such asanatomical information provided by one or more ultrasound transducers ofthe present invention and/or one or more electrodes of the presentinvention. This anatomical information includes but is not limited to:two or three dimensional representations of tissue such as one or morechambers of a heart; tissue wall thicknesses such as the thickness of anatrial or ventricular wall; distance between two tissue surfaces; andcombinations of these. In some embodiments, a dipole density map isprovided by using information provided by multiple electrodes andmultiple ultrasound transducers, such as is described in Applicant'sco-pending international application, Serial Number PCT/US2012/028593,entitled Device and Method For the Geometric Determination of ElectricalDipole Densities on the Cardiac Wall, the entirety of which isincorporated herein.

The terms “device map” and “device mapping” shall include recording,processing and/or displaying of device distance information such asinformation comprising the distance between a device or device componentand another object, such as tissue or another device or devicecomponent.

Any pair of electrodes of the present invention can be constructed andarranged to provide distance information, such as the distance betweenthat pair of electrodes, or the distance between one of the electrodesand one or more proximate components (e.g. a component at a knowndistance from one or both of the electrodes in the pair). By deliveringand recording an electric signal between electrodes of known separationdistances, the signal can by processed and/or calibrated according toone or more known separation distances (e.g. the separation distancebetween two electrodes fixedly mounted to a rigid structure at apre-determined distance). Calibrated signal values can be combinedacross adjacent sets of electrode pairs to accurately estimate thedistance between any pair (e.g. any arbitrary pair of electrodes on anyone or more devices of the system) of electrodes for which theseparation distance is not known. Known and calculated separationdistances can be used as “reference” electrodes and combined totriangulate the unknown position of one or more “marker” electrodes,such as an electrode positioned on the present invention or on aseparate or external device and positioned proximate the presentinvention. The process of triangulation can be used to dynamicallylocalize the three-dimensional position of any or all of the electrodeseither individually and/or as a combined entity in three dimensional(3D) space. Numerous distance measurement techniques are described indetail in reference to FIGS. 2A and 2B herebelow.

Further, any or all electrodes of the present invention can be used todeliver electric energy, such as radiofrequency energy.

Referring now to FIG. 1A, a perspective view of the distal portion of asystem for diagnosing and/or treating a heart arrhythmia, such as atrialfibrillation and/or ventricular tachycardia, is illustrated. The systemincludes an ablation catheter slidingly received by the shaft of adiagnostic catheter. System 10 includes diagnostic catheter 100 which isconstructed and arranged for insertion into a body location, such as thechamber of a heart. Catheter 100 includes shaft 120, typicallyconstructed of sufficiently flexible material to allow insertion throughthe tortuosity imposed by the patient's vascular system. On the distalportion of shaft 120 is an expandable assembly 130 which includes aplurality of electrodes 141 coupled thereon. Additionally, a pluralityof ultrasound transducers 151 are coupled to expandable assembly 130.System 10 further includes ablation catheter 200, which includes shaft220. Shaft 220 includes at least one ablation element 261, positioned atthe tip or otherwise on a distal portion of shaft 220. Ablation element261 is constructed and arranged to deliver energy to tissue, such aswhen ablation catheter 200 is attached to a source of energy as isdescribed in reference to FIG. 6 herebelow.

Shaft 120 includes a lumen 126 traveling from at least a proximalportion of shaft 120 (e.g. from a handle, not shown but typicallypositioned on shaft 120's proximal end) to a distal portion of shaft 120(e.g. to shaft 120's distal end). Shaft 220 of ablation catheter 200 andlumen 126 of diagnostic catheter 100 are constructed and arranged toallow shaft 220 of ablation catheter 200 to be slidingly received bylumen 126. Lumen 126 can be further configured to slidingly receiveadditional catheters or other elongate devices, such as prior toinsertion of diagnostic catheter 100 into a body, or after diagnosticcatheter 100 has been inserted into a body.

Diagnostic catheter 100 can be used for mapping tissue such as an organor portion of an organ (e.g. a portion of a heart wall). Threedimensional anatomical mapping information collected by diagnosticcatheter 100 can be used by system 10 to create a three dimensionaldisplay of an anatomical location of which at least a portion is to betreated by ablation catheter 200. Diagnostic catheter 100 can be coupledto a computer system, not shown but configured to display anatomicalmapping information generated by diagnostic catheter 100 such asvolumes, locations, shapes, contours, and movement of organs, nerves,and other tissue within the body. Diagnostic catheter 100 can be coupledto the computer system to display the electrical mapping informationgenerated by diagnostic catheter 100, such as to display dipole mappingor other information as has been described above. Additionally, thelocation of ablation catheter 200 or other inserted devices can bedisplayed, such as their position relative to tissue or diagnosticcatheter 100. For example, diagnostic catheter 100 can be used to mapthe heart, while ablation catheter 200 can be directed to a tissuelocation in the heart targeted for treatment (e.g. targeted fortreatment based on information provided by diagnostic catheter 100). Forexample, ablation catheter 200 can be configured to ablate cardiactissue to treat a patient suffering from a cardiac arrhythmia, such asatrial fibrillation, atrial flutter, supraventricular tachycardias(SVT), Wolff-Parkinson-White syndrome, and ventricular tachycardias(VT). An ablation catheter will be described herein as a form of atreatment device for purposes of conveying aspects of the invention, buta different type of treatment device (e.g., a pacing device; adefibrillation device; a stent delivery device; a drug delivery device,a stem cell delivery device, or the like) can be used in otherembodiments in combination with diagnostic catheter 100. In someembodiments, one or more of these treatment devices is inserted througha lumen of diagnostic catheter 100.

In some embodiments, system 10 is configured to access the left atriumof the patient while utilizing a single transseptal puncture throughwhich all the catheter components of system 10 access the left atrium(and subsequently the left ventricle in some cases). In otherembodiments, system 10 is configured to access the left ventricle of thepatient while utilizing a single crossing of the aortic valve throughwhich all the catheter components of system 10 access the left ventricle(and subsequently the left atrium in some cases). System 10 can includesheath 50, for example a standard access sheath, such as a standardtransseptal access sheath. In some methods, sheath 50 is insertedthrough the atrial septum and into the left atrium, followed by theinsertion of diagnostic catheter 100 through a lumen of sheath 50.Subsequently, ablation catheter 200 is inserted through lumen 126 ofdiagnostic catheter 100. In other methods, sheath 50 is inserted intothe left atrium, followed by the simultaneous insertion of diagnosticcatheter 100 and ablation catheter 200 (e.g. diagnostic catheter 100 isinserted with ablation catheter 200 residing at least partially withinlumen 126). In some embodiments, sheath 50 can include a steerablesheath. Shaft 120 comprises a diameter along the majority of its lengthsuch as to be slidingly received by sheath 50. In some embodiments,shaft 120 comprises a diameter less than or equal to 15 Fr. In someembodiments, diagnostic catheter 100 and/or ablation catheter 200 aresteerable, such as is described in reference to FIGS. 3 and 6 herebelow,so as manual, semi-automatic or automatic steering can be performed byan operator and/or a robotic control assembly of system 10.

Diagnostic catheter 100 can be positioned in the left atrium and canprovide information selected from the group consisting of: electricalinformation such as surface charge information; anatomical geometryinformation such as heart wall surface information or heart wallthickness information; other physiologic and anatomical information suchas those described herein; and combinations of these. Shaft 120 ofdiagnostic catheter 100 can be configured to be inserted into the heartvia the venous system, for example a vein in a leg or a vein in a neck.Shaft 120 can include a braid within its outer and inner surfaces, notshown but typically a braid of plastic or metal fibers that enhance thestructural integrity and performance of shaft 120. In some embodiments,the braid of shaft 120 can include conductors, such as is described inreference to FIG. 3 herebelow.

As described above, diagnostic catheter 100 of FIG. 1A includes lumen126 extending from a proximal portion to a distal portion of shaft 120,for example from a proximal end to a distal end of shaft 120 so as toallow a separate catheter or other elongate device to be insertedtherethrough, such as ablation catheter 200, as shown. Alternatively oradditionally, the inserted catheter or other elongate device can includea diagnostic catheter such as a diagnostic catheter configured to recordsignals from a location selected from the group consisting of: the leftatrium; the right atrium; the Bundle of HIS; the right ventricular apex;a pulmonary vein; the coronary sinus. Alternatively or additionally, theinserted catheter can comprise another catheter device, such as catheterdevice 700 described in reference to FIG. 6 herebelow.

Diagnostic catheter 100 of FIG. 1A includes expandable assembly 130,which is positioned at the distal end of shaft 120. As illustrated,expandable assembly 130 includes an array of splines 131, each spline131 having proximal segment 132, middle portion 134, and distal segment133. Proximal segment 132 of each spline 131 connects to shaft 120, viaconnection point 127, described in detail in reference to FIG. 2herebelow. The distal ends of each spline 131 connect in acircumferential ring configuration to form opening 135. Opening 135allows a device to pass therethrough such as a device inserted intolumen 126, for example shaft 220 of ablation catheter 200. In someembodiments, expandable assembly 130 can include one or more guideelements configured to guide a device through opening 135, guideelements not shown but described in detail in FIGS. 7A-B herebelow.

Expandable assembly 130 is constructed and arranged to be positioned inthe expanded shape shown in FIG. 1A. The expanded geometry of assembly130, including at least two or more splines 131 in an expanded orpartially expanded state (hereinafter “expanded state”), can bedescribed as a “basket” having a substantially hollow center and spacesbetween adjacent splines 131. In the illustrated embodiment, the basketis spherical, but can include any suitable shape, for example anellipsoid. Thus, in other embodiments, assembly 130 can comprisedifferent shapes or combination of shapes, such as an array of splines131 where two or more splines 131 comprise similar or dissimilar shapes,dimensions or configurations. In some embodiments, two or more splines131 include a varied radius of curvature.

Expandable assembly 130 can be biased in an expanded or non-expandedstate. In an example, assembly 130 can be self-expanding such thatsplines 131 are resiliently biased in the curved geometry shown in FIG.1A. Assembly 130 can automatically expand when assembly 130 exits thedistal end of sheath 50, such as by advancement of shaft 120 and/orretraction of sheath 50. Alternatively, assembly 130 can be manuallyexpanded, for example via retraction of a rod 129 that slides withinshaft 120 and is connected to distal end of assembly 130, as describedin detail in reference to FIG. 2 herebelow.

Splines 131 can be constructed of a material selected from the groupconsisting of: one or more thermoplastic polymers such as polyetherblock amide, polyurethane and/or polyether ether ketone; one or more ofthermoset polymers such as silicon and/or tetrafluoroethylene; one ormore metals such as stainless steel and/or shaped memory alloys such asnickel titanium alloy; one or more shape memory polymers such as tripleshape acrylic; and combinations of these. Generally, any of a number ofmaterials or compositions that are biocompatible, flexible or bendable,and possess any necessary application specific electrical properties canbe used for splines 131.

Splines 131 can include one or more electrodes 141 and/or one or moreultrasound transducers 151 arranged in any combination. For example, insome embodiments, one or more of the following configurations isincluded: each spline 131 includes at least four, six or eightelectrodes 141; each spline 131 includes at least four, six or eightultrasound transducers 151; and combinations of these. In someembodiments, at least one electrode 141 is positioned between twoultrasound transducers 151 on a single spline 131. In some embodiments,at least two electrodes 141 are positioned between two ultrasoundtransducers 151 on a single spline 131.

Each spline 131 can include a similar or dissimilar arrangement ofelectrodes 141 and/or ultrasound transducers 151 as an adjacent spline131 or any other spline 131 in assembly 130. In some embodiments,assembly 130 includes eight splines 131, where each spline 131 caninclude two to eight electrodes 141 and two to eight ultrasoundtransducers 151. In some embodiments, assembly 130 includes six splines131, where each spline 131 can include eight electrodes 141 and eightultrasound transducers 151. In some embodiments, one or more splines 131include a number of electrodes 141 that comprises a quantity within oneof the quantity of ultrasound transducers 151 that are included on thatspline 131. For example, a spline 131 can include seven electrodes 141and either six or eight ultrasound transducers 151. In some embodiments,a set of electrodes 141 and ultrasound transducers 151 can be arrangedin an alternating arrangement, such that one or more single ultrasoundtransducers 151 lies between two electrodes 141. In some embodiments,some sets of electrodes 141 and ultrasound transducers 151 can bearranged such that one or more single electrodes 141 is positionedbetween two ultrasound transducers 151.

Electrodes 141 can be configured to record electric signals such asvoltage and/or current signals. System 10 can utilize the recordedsignals to produce electrogram information; dipole mapping information;distance information such as the distance between any device and/orcomponent of system 10; and other information or combinations ofinformation described in detail herein. Any or all electrodes 141 ofsystem 10 can comprise a dipole mapping electrode, such as an electrodewith a impedance or other electrical property configured to provideinformation related to surface charge or other dipole mapping parameter.In some embodiments, the electrodes 141 are of sufficiently lowimpedance, such as in the range less than 10,000 ohms, such as toachieve high-fidelity recording of signal frequencies greater than orequal to 0.1 Hz. In some embodiments, one or more electrodes 141 includean iridium oxide coating, such as to reduce the impedance of electrodes141. Alternatively or additionally, numerous forms of coatings or othertreatments can be included with one or more electrodes 141, such as aplatinum black coating or a carbon nanotube layer. In addition or as analternative to recording electric signals, electrodes 141 can beconstructed and arranged to deliver electric energy, such asradiofrequency energy. In some embodiments, diagnostic catheter 100 candeliver therapy, such as an ablation therapy delivered to tissue, inaddition to its function as a diagnostic catheter, e.g. providingelectrical, anatomical and/or device mapping information. In someembodiments, one or more electrodes 141 each comprise one or more coils,such as when the one or more coils are configured to create one or moremagnetic fields.

Electrodes 141 can include various materials such as non-polarizingmetals and/or polarizing metals. In some embodiments, one or moreelectrodes 141 comprise at least one non-noble metal such thatelectrodes 141 oxidize when in contact with at least one of blood, bloodplasma or saline solutions. In some embodiments, electrodes 141 includea coating, for example a coating selected from the group consisting of:a metal oxide coating; a conductive polymer coating; and combinations ofthese. In some embodiments, one or more electrodes 141 can include anouter layer and an inner layer, such as when the outer layer comprisesan impedance lowering coating or other layer and the inner layercomprises a layer configured to bond the outer layer to the metallicand/or other remaining portion of the one or more electrodes 141.

Ultrasound transducers 151 can be configured to record distanceinformation such as the distance between any device and/or component ofsystem 10 and tissue such as cardiac wall or other solid tissue.Ultrasound transducers 151 can include a construction comprising: singleor multi-element piezoelectric ceramics; piezoelectric micro-machinedultrasound transducers (pMUT); capacitive micro-machined ultrasoundtransducers (cMUT); piezoelectric polymers; and combinations of these.

In some embodiments, diagnostic catheter 100 can include a multi-layeror laminate construction, for example where shaft 120 includes a tubeinside of another tube; where shaft 120 includes a liner such as alubricous liner such as PTFE; where shaft 120 includes a braidedconstruction such as a braid positioned between two layers of shaft 120;and combinations of these. In some embodiments, diagnostic catheter 100can be steerable, for example via the incorporation of a pull wire andanchor as shown and described in reference to FIG. 3 herebelow.Typically, diagnostic catheter shaft 120 outer diameter is less than 15Fr.

Ablation catheter 200 of FIG. 1A includes ablation element 261positioned on shaft 220, for example on a distal portion or the distaltip of shaft 220. Ablation element 261 can include a functional elementselected from the group consisting of: one or more electrodes; a vesselconfigured to deliver cryogenic energy; a laser diode; an optical fiberconfigured to deliver ablative energy; a microwave energy deliveryelement; an ultrasound energy delivery element; a drug, stem cell, orother agent delivery element; a mechanical or other ablation devicedelivery element; and combinations of these. In the case where ablationelement 261 includes one or more electrodes, the electrodes can includeelectrodes constructed and arranged to deliver radiofrequency (RF)energy. In the case of multiple electrodes, the electrodes can beconfigured for bipolar RF energy delivery. In some embodiments, ablationelement 261 includes an array of elements such as in one or more of thecomponent array configurations shown in FIG. 6. Ablation catheter 200can be operably connected to a device configured to deliver energy toablation element 261, such as energy delivery unit 400 of FIG. 6.Typical energy delivered by ablation element 261 comprises an energyselected from the group consisting of: electromagnetic energy such asradiofrequency energy; cryogenic energy; laser energy; light energy;microwave energy; ultrasound energy; chemical energy; and combinationsof these.

Similar to diagnostic catheter 100 and sheath 50, ablation catheter 200can be steerable, such as via a pull wire and anchor as described inreference to FIG. 3 herebelow. Referring now to FIG. 1B, distal portion225 of ablation catheter 200 has been steered in the curved geometryshown to cause ablation element 261 to exit expandable assembly 130 ofdiagnostic catheter 100, passing between two middle portions 134 of twosplines 131. Ablation catheter 200 can be steered and advanced by anoperator such as a clinician, so as to exit at any opening of theexpandable assembly 130, including the space between two splines 131 orthrough opening 135, such as to be further advanced to contact andablate cardiac tissue.

Referring now to FIG. 2, a perspective view of the distal portion of thesystem of FIGS. 1A and 1B is illustrated, including a push rod operablyattached to expandable assembly 130. System 10 includes diagnosticcatheter 100 and ablation catheter 200. Diagnostic catheter 100comprises an elongate shaft 120 which includes lumen 126 exiting itsdistal end. Ablation catheter 200, which has been removed for clarity,is configured to be slidingly received by lumen 126. Diagnostic catheter100 includes push rod 129, typically a solid tube or hypotube slidinglyreceived within a wall or a lumen of shaft 120, that can be used toexpand or collapse (i.e. un-expand or compact) expandable assembly 130.Push rod 129 can be operably attached to a handle, not shown buttypically a handle including one or more controls used to advance orretract push rod 129 and/or steer one or more catheter shafts. In someembodiments, retracting rod 129 causes assembly 130 to expand (e.g. thebackward force applied on the distal end of assembly 130 by rod 129causes splines 131 to bow), and advancing rod 129 causes assembly 130 tocollapse (e.g. the forward force applied on the distal end of assembly130 by rod 129 causes splines 131 to straighten).

As illustrated in FIG. 2, expandable assembly 130 includes an array ofsplines 131, each spline 131 having proximal segment 132, middle portion134 and distal segment 133. Distal segments 133 of each spline 131connect in a circumferential ring configuration to form opening 135,which is relatively orthogonal to and relatively centrally positionedabout axis “A”, which comprises the central axis of the distal portionof shaft 120. Opening 135 allows the distal portion of a shaft of adevice to pass therethrough, such as a device inserted into lumen 126,for example shaft 220 of ablation catheter 200 of FIGS. 1A and 1B.Proximal segment 132 of each spline 131 connects to shaft 120 viaconnection points 127. A mechanical attachment can be made between anyspline 131 and shaft 120 at connection points 127, such as an attachmentcomprising a compression fitting or adhesive. Any spline 131 can beattached to shaft 120 at connection point 127 via a bonding process,such as a thermal bonding process where a spline 131 is positioned inthe wall of shaft 120 or when shaft 120 comprises two polymer coaxialtubes and spline 131 is thermally set between the tubes. Alternativelyor additionally, adhesive bonds, mechanical crimps or and/or other bondscan be used. Proximal segments 132 are convex with respect to centralaxis “A” of the distal portion of shaft 120. Proximal segments 132 cantransition to middle portions 134 through an inflection point, such thatmiddle portions 134 and distal segments 133 are concave with respect toaxis “A”. In some embodiments, the radius of curvature of proximalsegment 132 ranges from approximately 0.01 mm to 25 mm, or larger. Whenproximal segments 132 engage the lumen of sheath 50, such as while shaft120 is being retracted, a compressing force is applied to proximalsegments 132 by sheath 50, initiating the radial compression of assembly130. Continued retracting of shaft 120 causes assembly 130 to be fullycaptured within sheath 50 and maintained in an unexpanded state. Theconvexity of proximal segments 132 can be chosen to allow smooth captureof assembly 130 by sheath 50, avoiding any undesired threshold forcesrequired to initiate the radial compression of assembly 130. Otherconfigurations for proximal segments 132 can be used to facilitate asmooth transition from the expanded state to the unexpanded, capturedstate. In some embodiments, push rod 129 can be partially advanced, suchas to partially collapse expandable assembly 130, initiating radialcompression of assembly 130, thus facilitating an easier capture ofsplines 131 by sheath 50.

Referring now to FIG. 2A, a magnified view of a portion of a spline ofthe diagnostic catheter 100 of FIG. 2 is illustrated, including oneultrasound transducer and two adjacent electrodes. In some embodiments,diagnostic catheter 100 includes an equal number of ultrasoundtransducers 151 and electrodes 141, such as an array comprisingforty-eight ultrasound transducers 151 and forty-eight electrodes 141.

In some embodiments, relative positions of splines 131, electrodes 141,and ultrasound transducers 151 of expandable assembly 130 are of knownvalues, such as when expandable assembly 130 is in a pre-configured“biased” state (e.g. a resiliently biased, fully expanded state with noforces applied). These known values can be correlated to a 3D coordinatesystem, such as a Cartesian coordinate system; a spherical coordinatesystem; and/or a coordinate system with an origin at the center of theexpandable array or any location. The origin of a coordinate system canbe used to map the location of one or more of: one or more components ofdiagnostic catheter 100 such as one or more splines 131, one or moreelectrodes 141 or one or more ultrasound transducers 151; one or morecomponents of ablation catheter 200 of FIGS. 1A and 1B such as ablationelement 261; one or more components of a separate device inserted intothe patient; one or more components of a separate device external to thepatient; one or more portions of the patient's anatomy. Other portionsof diagnostic catheter, as well as anatomical features measured bydiagnostic catheter 100, can be located at a useful position forperforming a medical procedure, such as at the distal end of shaft 120,the distal tip of expandable assembly 130, the geometric center ofexpandable assembly 130, any electrode 141 or ultrasound transducer 151,or any other useful location.

In some embodiments, diagnostic catheter 100 utilizes three or moreelectrodes 141 (e.g. any three electrodes 141) as a reference. The threeor more electrodes 141 can be used to triangulate the position of amarker electrode, such as an electrode on a separate device andpositioned proximate expandable assembly 130. Each of the referenceelectrodes can be configured to emit an electric signal, with the threesignals comprising three similar waveforms with the exception of a phaseshift of 120° between them. A marker electrode can record a combinedsummation of the three phase shifted signals. This combined signal canbe used (e.g. by one or more components of a system such as system 10 ofFIG. 6 herebelow) to determine the position of the marker electrode inrelation to the three electrodes, such as by using one or moretriangulation algorithms. For example, if the marker electrode is at ageometric center of the three electrodes, the resultant electric signalwill be zero. Non-zero readings are analyzed to determine the distancefrom each reference electrode to the marker electrode. Precision ofmarker electrode position can be improved by having additionalelectrodes 141 (e.g. four or more) emit a signal to be recorded by themarker electrode with values to be processed by a positioning algorithm.

In some embodiments, three or more reference electrodes emit an electricsignal, such as an electric signal provided by a component of a system,such as system 10 of FIG. 6 described herebelow. Such referenceelectrodes can be located in various locations, such as a locationselected from the group consisting of: on diagnostic catheter 100; on anablation catheter such as ablation catheter 200 of FIGS. 1 and 6described herein; on one or more separate devices, such as one or moreseparate devices proximate expandable assembly 130; on one or morelocations on the surface of the body; and combinations of these. Eachreference electrode can sequentially emit a signal at the same frequencyor simultaneously emit signals at different frequencies. Three or moremarker electrodes record signals with values that differ inlogarithmic-proportion to the separation distance between the referenceelectrodes and the marker electrodes. A set of three or more such markerelectrodes can be comprised of any electrode 141 located on diagnosticcatheter 100 or any two or more of any electrodes 141 located ondiagnostic catheter 100 in combination with any one or more electrodeslocated on one or more separate devices positioned proximate expandableassembly 130. Recorded differences in signal-values by the markerelectrodes can be combined to determine the position of the markerelectrodes in relation to the reference electrodes, such as by using oneor more triangulation algorithms. For example, if two or more markerelectrodes are equidistant from any reference electrode, thecorresponding recorded signal-values on each marker electrode will beequal in magnitude. Conversely, the values of the recorded signals willbe unequal to each other in logarithmic-proportion to the amount bywhich each marker-electrode-to-reference-electrode separation distancesare unequal. By combining the recorded signal-values with a geometricpolyhedron connecting each individual reference electrode and the markerelectrodes (e.g. a tetrahedron in the case of one reference electrodeand three marker electrodes), the volume of the polyhedron can beanalyzed to triangulate the position of the marker electrodes. Precisionof the marker electrode positions can be improved by having additionalneighboring sets of reference and marker electrodes that emit and recordsignals, respectively, and by similarly analyzing the associated sets ofpolyhedral volumes and combining the results of triangulation.

In some embodiments, an electric signal is delivered between tworeference electrodes (i.e. emitted from a first electrode and “returned”to a second electrode), such as by a component of system, such as system10 of FIG. 6 described herebelow. Such reference electrodes arecomprised of any two of electrodes 141 located on diagnostic catheter100 or any one of electrodes 141 located on diagnostic catheter 100 incombination with any electrode located on any separate device positionedproximate expandable assembly 130 or on any electrode located on thebody surface. Three or more marker electrodes located between andproximate the two reference electrodes record signals with values thatdiffer in logarithmic-proportion to the separation distance between eachof the two reference electrodes and the marker electrodes. Any three ormore such marker electrodes are comprised of any electrode 141 locatedon diagnostic catheter 100 or any two or more of any electrode 141located on diagnostic catheter 100 in combination with any one or moreelectrodes located on one or more separate devices positioned proximateexpandable assembly 130. Recorded differences in signal values can becombined to determine the position of the marker electrodes in relationto the resultant electric field generated by the signal deliveredbetween the two reference electrodes. One or more geometric shapealgorithms can be used for which the recorded signal values compriseshape parameters that conform to the geometric shape of the resultantelectric field between and proximate all of the marker electrodes (e.g.such parameters that quantify how much the shape of the resultantelectric field is spheroidal, oblate, prolate, eccentric, skewed,rotated and/or, offset). Precision of the marker electrode determinedpositions can be improved by increasing the number of marker electrodesthat are used to parameterize the shape of the resultant electric fieldand/or by using additional unique neighboring pairs of referenceelectrodes to generate the resultant electric field across unique spansof the 3D space between and proximate the marker electrodes. Theresultant marker field-values are recorded, the associated sets ofresultant electric field shapes are parameterized, and the parametersare combined into a common resultant shape. Signals of one frequency areapplied sequentially between multiple reference electrode-pairs andsignals with different frequencies can be applied simultaneously.

In any embodiment, one or more marker electrodes can comprise anablation element (e.g. to deliver RF energy), or it can be at a knownposition relative to an ablation element or other component of a deviceof a system, such as system 10 of FIG. 6 described herebelow.

Referring now to FIG. 2B, a side view of a segment of a spline disposedproximate to tissue is illustrated. Spline 131 is positioned proximatetissue (“TISSUE”) and includes ultrasound transducers 151 a and 151 b asshown. Spline 131 further includes electrodes 141 a, 141 b, 141 c and141 d as shown. Ultrasound transducers 151 a, 151 b can be used toprovide distance information, such as the distance between eachultrasound transducer 151 a, 151 b and TISSUE. This distance informationcan be used to determine the distance between one or more electrodes 141a, 141 b, 141 c, 141 d and TISSUE, for example by using the knowndistance between one or more electrodes 141 a, 141 b, 141 c, 141 d andone or more ultrasound transducers 151 a, 151 b, as well as a known ormeasured shape of spline 131. That is, the distance between anyultrasound transducer and any electrode (e.g. d1 or d1′ as shown) isknown or can be calculated by the system of the present invention (e.g.a calculation to account for distance changes due to bending of splines131). Accordingly, a distance between any ultrasound transducer andTISSUE can be determined according to traditional ultrasound algorithms,for example the distances between ultrasound transducer 151 a and 151 band TISSUE, represented by d2 and d2′, respectively. As a result, adistance between any electrode and TISSUE can be calculated, for examplethe distance between electrodes 141 a, 141 b, 141 c and 141 d andTISSUE, represented by d3, d3′, d3″, and d3′″, respectively.

If one or more forces are imparted on any spline 131, the spline canchange shape. Alternatively or additionally, an imparted force on anyspline 131 can cause that spline 131 to move in relation to anotherspline 131. Systems of the present invention can be constructed andarranged to measure these geometric changes to one or more splines 131.In some embodiments, electrical information can be collected by one ormore electrodes 141 to measure one or more distances, and one or morealgorithms of system 10 use the one or more measured distances todetermine a geometric configuration of one or more splines 131. In someembodiments, a current is applied between any two electrodes 141, andthe distance between the two electrodes 141 can be determined, such aswith one or more algorithms to determine a distance, as is described indetail in reference to FIG. 2A hereabove.

Distance information can be used by one or more algorithms of system 10to derive the real-time shape or relative positioning of one or moresplines 131. The shape of a spline 131 and the distance between twoelectrodes 141 positioned on spline 131 is known, when spline 131 is inan equilibrium (e.g. resiliently biased) state. Measurement of a changeto the equilibrium separation distance between two electrodes 141positioned on a single spline 131 can be used by an algorithm of system10 to determine the change in shape to the spline 131 as one or moreforces are applied (e.g. as a spline 131 is pressed against a heartwall). In some embodiments, increased bowing of a spline 131 can causethe electrode 141 separation distance to decrease, and straightening ofa spline 131 can cause the electrode 141 separation distance toincrease, each in a predictable manner. Similarly, when an array ofsplines 131 are in an equilibrium state, the distance between a firstelectrode 141 on a first spline 131 and second electrode 141 on a secondspline 131 is also known. Measurement of a change in the separationdistance between these two electrodes 141 positioned on two splines 131can be used to determine a change in relative positioning of the twosplines 131 as one or more forces are applied (e.g. as a spline 131 ispressed against a heart wall).

Similarly, the distance between any two electrodes positioned on any twoseparate devices can be determined by an algorithm of system 10, such asthe distance between one or more portions of diagnostic catheter 100 andone or more portions of ablation catheter 200, each described inreference to FIGS. 1 and 6. Another algorithm of system 10 can includemeasuring the distance between an electrode positioned on diagnosticcatheter 100 and an electrode positioned on a third catheter device suchas catheters 500 and 600 described in FIG. 6 herebelow. This measurementcan be repeated between any two electrodes positioned on any device, atany time during the clinical procedure. This distance information can beuseful to determine the geometry of an expandable assembly, such asexpandable assembly 130 described herein, when the known expandedgeometry has changed, for example when a force is exerted by a tissuewall on assembly 130. System 10 can include one or more algorithms thatuse distance information data to localize, or allow an operator tolocalize, one or more devices of system 10. Alternatively oradditionally, system 10 can include one or more algorithms that usedistance information data to navigate, or allow an operator to navigate,one or more devices of system 10. The localization and/or navigation cancomprise real-time or near real-time localization and/or navigation. Thesignals applied to any of the electrodes of system 10 can includeconstant or variable currents and/or voltages and/or other processedvalues.

Referring now to FIG. 3, a side view of a distal portion of the systemof FIG. 1A is illustrated, where the diagnostic catheter has beenretracted into the sheath. Diagnostic catheter 100 has been retractedinto sheath 50 such that splines 131 and other components of expandableassembly 130 are in a collapsed or unexpanded state. Ablation catheter200 has been slightly retracted into shaft 120 of diagnostic catheter100 such that ablative element 261 remains partially exposed. Retractionof diagnostic catheter 100 and/or ablation catheter 200 can be performedby an operator grasping the relevant proximal portion (e.g. a handle)and moving the device proximally relative to sheath 50.

Shaft 120 of diagnostic catheter 100 can include braid 121. In someembodiments, braid 121 is positioned between an inner layer and an outerlayer of shaft 120. Portions or all of braid 121 can include conductors,for example a helical or other arrangement of conductors integral to,positioned within and/or passing through braid 121 and operablyconnected to electrodes 141 and/or ultrasound transducers 151. In theillustrated embodiment, conductor 125 connects to wire 142 at connectionpoint 143 (e.g. a solder connection point that operably connects toelectrode 141). Similarly, conductor 124 connects to wire 152 atconnection point 153 (e.g. a solder connection point that operablyconnects to ultrasound transducer 151). In some embodiments, conductors124 and/or 125 include a standard wire with an insulation covering.Alternatively, conductors 124 and/or 125 include a coaxial cable, suchas a coaxial cable with a diameter of approximately less than 0.012inches. In some embodiments, conductors 124 and/or 125 are not part ofbraid 121, but rather pass through braid 121 and/or pass along an inneror outer surface of braid 121.

Also shown in FIG. 3 is the inclusion of pull wires and anchors forsheath 50, diagnostic catheter 100 and ablation catheter 200, each setconfigured to steer their respective device. Sheath 50 includes pullwire 52 and anchor 53 which can be connected to a lever, a cam, or otherwire control mechanism which is operably connected to a knob or slidepositioned on a handle, all not shown but located at a proximal end ofsheath 50. Similarly, diagnostic catheter 100 includes pull wire 122 andanchor 123, and ablation catheter 200 includes pull wire 222 and anchor223, each pull wire 122 and 222 typically controlled as described aboveby a control on a handle. Each device can be independently controlledvia its respective steering pull wire and anchor, however if desired twoor more devices can be controlled in concert, such as via a singlecontrol. Each device can comprise multiple pull wires, not shown butconfigured to provide multiple degrees of steering freedom.

Referring now to FIG. 4, a flow chart of a method for mapping a 3-Dspace within a body using the system of the present invention isillustrated. In STEP 902, a diagnostic catheter is inserted into a heartchamber, for example the left atrium, the right atrium, the leftventricle, or the right ventricle. The diagnostic catheter can be thesame as or similar to diagnostic catheter 100 described herein. Thediagnostic catheter can be inserted through previously insertedtransseptal sheath, for example sheath 50 described herein. Thediagnostic catheter includes one or more distance measurement elements,such as ultrasound transducers 151 described herein. A treatment devicesuch as ablation catheter 200 can also be inserted into a heart chamber,either simultaneously with the diagnostic catheter (e.g. when theablation catheter shaft resides within a lumen of the diagnosticcatheter), or it can be inserted subsequent to the insertion of thediagnostic catheter, for example at a time after a 3-D map of the heartchamber has been created. The treatment device can be inserted through alumen of the diagnostic catheter so that only a single transseptalpuncture is required, as has been described in reference to FIG. 1Ahereabove.

In STEP 904, a first set of surface data is collected via one or moreultrasound transducers positioned on the diagnostic catheter such asultrasound transducers 151 described herein. Alternatively oradditionally, surface data can be collected from ultrasound transducerspositioned on a separate device such as device 200, 500, 600, 700 and/oran external device such as an external ultrasound device or otheraccessory device such as device 800 of FIG. 6. Data collected from theultrasound transducers of device 100, 200, 500, 600, 700, and/or 800 caninclude distance information such as the distance from any ultrasoundtransducer to tissue such as cardiac tissue. Optionally, electricalinformation can also be collected via one or more electrodes positionedon a device, such as electrodes 141 described herein, or one or moreelectrodes positioned on one or more devices such as devices 100, 200,500, 600 and/or 700 described herein. The electrical information can beused to determine distances between devices or device components, and itcan be used to determine a geometric change in a device that occurs whena force is imparted, such as by using the algorithms described inreference to FIG. 2B hereabove. The electrical information can becollected simultaneously or synchronously with the data collected fromthe ultrasound transducers. In some embodiments, data is collectedduring multiple heart cycles where sequential sets of data can becorrelated to a particular point in the heart cycle, for example datasets that are coordinated with a surface ECG recording that issimultaneously collected.

In STEP 906, the diagnostic catheter and/or any device includingultrasound transducers and/or electrodes is repositioned within theheart chamber so that a next set of surface data can be collected,similar to the collection of data in STEP 904.

In STEP 908, any or all sets of collected surface data are combined viaa signal processing unit, for example signal processing unit 300 of FIG.6. Multiple sets of ultrasound distances can be combined to generate apoint cloud of surface points. When enough points are combined tosatisfy a threshold for density and uniformity of distribution, ahigh-resolution reconstruction of the chamber surface can be “meshed”across the point cloud and displayed as an anatomical three-dimensionalmodel. To reach this threshold, the relative position of the array islocalized through time so that all subsequent acquired distances aretranslated back to a universal origin in the coordinate system andthereby combined into a single set of surface points. Once surfacereconstruction is complete, the distances from the surface to anyelement and the voltage reading of that element can be used to calculatecharge source values with respect to time. The charge source values;unipolar voltage or bipolar voltage values; monophasic action potentialvalues; or other processed physiologic parameters; and combinations ofthese, can then be displayed upon the surface reconstruction.

In STEP 910, the signal processing unit can include an algorithm todetermine or to assist in determining if the combined data is sufficientfor display. This step can be a manual step, for example where aclinician can determine if the data is sufficient based on one or moreoutputs provided by the signal processing unit. Alternatively oradditionally, this can be an automated step, for example where athreshold algorithm of the signal processing unit determines if the datapoints are within a particular range of values, or if the amount ofcollected data points meet a minimum number of sufficient data points.If the data points are determined to be insufficient, the method repeatsbeginning at STEP 906 where a next set of data is collected.

If the data is found to be sufficient in STEP 910, the method proceedsto STEP 912 where a 3-D map is displayed. The surface data collectedfrom the ultrasound transducers or other transducers can be used tocreate an anatomical map of the heart chamber, and the surface datacollected from the electrodes or other sensors can be used to create anelectrical map of the heart chamber. The anatomical and electrical mapscan be superimposed on one another. Using the electrical data, analgorithm can be employed to create a dipole density map. Detailsrelated to an applicable algorithm is disclosed in Applicant'sco-pending international application, Serial Number PCT/US2012/028593,entitled Device and Method For the Geometric Determination of ElectricalDipole Densities on the Cardiac Wall, the entirety of which isincorporated herein. The anatomical and electrical maps can be overlaidto create a comprehensive 3-D map of the heart chamber. The data canrepresent a sequential set of data points corresponding to the beatingcycle of the heart and associated heart wall motion (e.g. the repeatedcycles of systole and diastole).

All data can be stored in memory by the signal processing unit oranother component of the system of the present invention, such as forfurther processing, playback, or any other desired presentation oranalysis.

Referring now to FIG. 5, a flow chart of a method for localizing anablation catheter within a body using the system of the presentinvention is illustrated. In STEP 922, a 3-D electrical and/oranatomical map of a heart chamber is created, for example via the methoddisclosed in FIG. 4.

In STEP 924, an ablation catheter is positioned within the mapped heartchamber. The ablation catheter can be the same as or similar to ablationcatheter 200 and/or 600 described herein. In one embodiment, theablation catheter can be inserted in a lumen of a diagnostic catheter,for example diagnostic catheter 100 as has been described herein.

In STEP 926, the ablation catheter is located, such as a location inrelation to the patient's anatomy and/or another device of the system ofthe present invention. An ablation catheter such as catheter 200 or 600of FIG. 6 can be located using a triangulation technique, such as thatdescribed in reference to FIG. 2 hereabove. The triangulation techniquecan utilize recorded signals from multiple electrodes positioned in anexpandable assembly, such as expandable assembly 130 described herein,and one or more energy delivery elements, such as electrodes 241 or 641of catheters 200 or 600, respectively, of FIG. 6.

In STEP 928, the ablation catheter is steered to target tissue underguidance, such as while being navigated by the system of the presentinvention using the triangulation techniques described herein. Detailrelated to an applicable steering mechanism is described in detail inreference to FIG. 3 hereabove. In one embodiment, the triangulationtechnique of FIG. 2A is repeated continuously or semi-continuously, suchas to provide a feedback loop used by an operator to steer the catheter.A feedback loop can include robotic or other automatic guidance of acatheter, for example a computer system, such as signal processing unit300 of FIG. 6, can control steering, advancement and/or retraction ofone or more catheters, such as via steering and linear motion assembliesin the handle of the catheter. In an alternate embodiment, visualfeedback can be provided to an operator, such that the operator canperform manual steering, advancement and retraction of one or morecatheters, while being provided catheter position information.

In STEP 930, the target tissue is ablated. The ablation catheterincludes an ablation element that can include one or more electrodes; anenergy delivery element configured to deliver cryogenic energy such as acryogenic balloon; a laser delivery element such as a laser diode; anoptical fiber configured to deliver ablative energy; a microwave energydelivery element; an ultrasound energy delivery element; a drug or otheragent delivery element; and combinations of these. In the case where theablation element includes one or more electrodes, the ablation elementcan include radiofrequency electrodes. In the case of multipleelectrodes, the electrodes can be configured for bipolar and/ormonopolar energy delivery. In some embodiments, the ablation elementincludes an array of elements such as in catheter 600 of FIG. 6.Further, the ablation catheter can be operably connected to an energydelivery unit, such as energy delivery unit 400 of FIG. 6.

STEPs 928 and 930 can be repeated one or more times, such as until thetreatment is complete or otherwise ceased.

Referring now to FIG. 6, a schematic of an embodiment of a mapping andablating system is illustrated. System 10 includes diagnostic catheter100 and can also include sheath 50, ablation catheter 200, seconddiagnostic catheter 500, second ablation catheter 600, and/or accessorycatheter device 700, each described in turn with reference to thisfigure. System 10 includes signal processing unit (SPU) 300, such as acomputer system used to receive signals to produce electrical,anatomical and/or device mapping information. System 10 can includeenergy delivery unit (EDU) 400, such as an electrical or other energydelivery system that provides energy to one or more ablation elements ofsystem 10, as are described herebelow. System 10 can include anaccessory device 800, such as an imaging device comprising an externallyapplied ultrasound probe. System 10 can include one or more visualdisplays, such as one or more visual displays integral to SPU 300, EDU400 or another device or component of system 10. The various componentsof system 10 can be electrically and/or mechanically connected by one ormore cables, such as cables including electric wires and/or opticalfibers to transmit data and/or power. In some embodiments, SPU 300, EDU400 and/or robotic control assembly 850 transfer information to or fromeach other, such as via the wired or wireless communication pathwaysshown in FIG. 6.

Diagnostic catheter 100 includes expandable assembly 130 positioned atthe distal end of shaft 120. Expandable assembly 130 can be resilientlybiased in the radially expanded position shown in FIG. 6 or it caninclude a means of manual expansion, such as has been describedhereabove. Expandable assembly 130 includes multiple splines 131, suchas splines 131 a and 131 b shown. The distal ends of splines 131 can beconfigured in a ring-shaped geometry, opening 135, such as is describedin reference to FIG. 1A hereabove. Expandable assembly 130 includeselectrodes 141 a and 141 b and ultrasound transducers 151 a and 151 b,having the same or similar functionality as electrodes 141 andultrasound transducers 151 described in FIG. 1A. Diagnostic catheter 100typically includes four or more electrodes 141, such as an array of twoto ten splines 131 where each spline 131 including four to tenelectrodes 141. Diagnostic catheter 100 typically includes four or moreultrasound transducers 151, such as an array of two to ten splines 131each spline 131 including four to ten ultrasound transducers 151.Diagnostic catheter 100 includes shaft 120 having a lumen configured toslidingly receive the shaft of a separate catheter, such as shaft 220 ofablation catheter 200. Handle 110, located at the proximal end of shaft120, includes pigtail 113 where one or more shafts, simultaneously orsequentially, can be inserted to enter lumen 126 and to exit the distalend of shaft 120. Diagnostic catheter 100 can be inserted into a heartchamber, for example via a transseptal sheath, such as sheath 50. Handle110 can include one or more controls, such as control 115. Control 115can be constructed and arranged to allow an operator to perform anaction selected from the group consisting of: steer shaft 120; radiallyexpand assembly 130; radially contract assembly 130; and combinations ofthese. Control 115 can be operably connected to a mechanism withinhandle 110, mechanism not shown but typically a mechanism selected fromthe group consisting of: a control cable motion assembly such as acontrol cable motion assembly connected to a steering pull wire asdescribed herein; a linear motion assembly constructed and arranged toadvance and/or retract a control rod such as a control rod attached toassembly 130 to expand and/or retract assembly 130 as described herein;and combinations of these.

System 10 can include first ablation catheter 200 having a similarconstruction to ablation catheter 200 of FIG. 1A. Ablation catheter 200includes handle 210 at the proximal end of shaft 220 and ablationelement 261 at the distal end of shaft 220. Ablation element 261 caninclude an electrode that is configured to receive one or more forms ofenergy. Ablation catheter 200 can include one or more electrodes 241 andone or more ultrasound transducers 251, having the same or similarfunctionality as electrodes 141 and ultrasound transducers 151 describedin reference to FIG. 1A hereabove, such as to provide anatomical,electrical and/or device mapping information to SPU 300 and/or anothercomponent of system 10. Handle 210 can include one or more controls suchas control 215. Control 215 can be constructed and arranged to allow anoperator to perform an action selected from the group consisting of:steer shaft 220; activate energy delivery by ablation element 261;adjust ablation delivery by ablation element 261; control an electricalconnection to electrode 241 and/or ultrasound transducer 251; andcombinations of these. Control 215 can be operably connected to amechanism within handle 210, mechanism not shown but typically amechanism selected from the group consisting of: a control cable motionassembly such as a control cable motion assembly connected to a steeringpull wire as described herein; a linear motion assembly constructed andarranged to advance and/or retract a control rod; an electric switch;and combinations of these.

System 10 can include second diagnostic catheter 500 having handle 510at the proximal end of shaft 520 and array 530 at the distal end ofshaft 520. Array 530 can include recording electrodes 591 configured torecord electrical activity. In one embodiment, array 530 can includeelectrodes 591 arranged in a spiral array so as to be placed in thecoronary sinus or a pulmonary vein, such as to record electricalactivity therein. Diagnostic catheter 500 can include one or moreelectrodes 541 and one or more ultrasound transducers 551, having thesame or similar functionality as electrodes 141 and ultrasoundtransducers 151 described in reference to FIG. 1A hereabove, such as toprovide anatomical, electrical and/or device mapping information to SPU300 and/or another component of system 10. Handle 510 can include one ormore controls such as control 515. Control 515 can be constructed andarranged to allow an operator to perform an action selected from thegroup consisting of: steer shaft 520; radially expand and/or contractarray 530; control an electrical connection to electrodes 591, electrode541 and/or ultrasound transducer 551; and combinations of these. Control515 can be operably connected to a mechanism within handle 510,mechanism not shown but typically a mechanism selected from the groupconsisting of: a control cable motion assembly such as a control cablemotion assembly connected to a steering pull wire as described herein; alinear motion assembly constructed and arranged to advance and/orretract a control rod; an electric switch; and combinations of these.

System 10 can include second ablation catheter 600 having handle 610 atthe proximal end of shaft 620 and array 630 at the distal end of shaft620. Array 630 can include electrodes 691 configured to recordelectrical activity. In one embodiment, array 630 can include electrodes691 arranged in a linear or a two-dimensional array. Ablation catheter600 can include one or more electrodes 641 and one or more ultrasoundtransducers 651, having the same or similar functionality as electrodes141 and ultrasound transducers 151 described in reference to FIG. 1Ahereabove, such as to provide anatomical, electrical and/or devicemapping information to SPU 300 and/or another component of system 10.Handle 610 can include one or more controls such as control 615. Control615 can be constructed and arranged to allow an operator to perform anaction selected from the group consisting of: steer shaft 620; radiallyexpand and/or contract expandable assembly 630; activate energy deliveryby electrodes 691; adjust energy delivery by electrodes 691; control anelectrical connection to electrode 641 and/or ultrasound transducer 651;and combinations of these. Control 615 can be operably connected to amechanism within handle 610, mechanism not shown but typically amechanism selected from the group consisting of: a control cable motionassembly such as a control cable motion assembly connected to a steeringpull wire as described herein; a linear motion assembly constructed andarranged to advance and/or retract a control rod; an electric switch;and combinations of these.

System 10 can include EDU 400 configured to deliver energy to any or allof the catheters and/or devices of system 10, for example catheters 100,200, 500, 600, and 700 via wires 112, 212, 512, 612, and 712,respectively. Typical energy types include but are not limited to:radiofrequency energy; cryogenic energy; laser energy; light energy;microwave energy; ultrasound energy; chemical energy; and combinationsof these. In one example, EDU 400 delivers energy to ablation element261 of ablation catheter 200. EDU 400 can provide ablation energy to anyablation element of system 10, such as electrodes 691 of ablationcatheter 600. System 10 can include grounding pad 420, shown attached tothe back of the patient P, such that EDU 400 can deliver monopolarradiofrequency energy, such as via treatment elements 261, electrodes691, or any electrode-based ablation element of system 10. EDU 400 canbe configured to deliver bipolar and/or unipolar radiofrequency energybetween any two electrodes in relative proximity to each other, such astwo electrodes 691 of ablation catheter 600.

System 10 includes SPU 300 configured to send and/or record signals toand/or from any or all of the catheters and/or devices of system 10, forexample catheters 100, 200, 500, 600, and 700 via wires 111, 211, 511,611, and 711, respectively. In some embodiments, SPU 300 can send and/orrecord signals to and/or from accessory device 800 and/or body surfaceelectrodes 820, such as when body surface electrodes 820 are positionedon the chest and abdomen of patient P as shown. For example, SPU 300 canrecord electric signals such as ultrasonic reflections from any or allof the ultrasound transducers of system 10 and can record current and/orvoltage signals from any or all of the electrodes of system 10. Theultrasound transducers can be included on any or all of the cathetersand/or other devices of system 10 (e.g. any of transducers 151 a, 151 b,251, 551, 651, and 751). Similarly, the recording electrodes can beincluded on any or all of the catheters and/or other devices of system10 (e.g. any of electrodes 141 a, 141 b, 241, 541, 641, and 741). Usingthe various recorded signals, SPU 300 can perform one or morealgorithmic functions and other mathematical calculations on dataextracted from the recorded signals. These calculations can result inoutput selected from the group consisting of: distance measurements;anatomical maps; device position maps; electrical maps; dipole maps; andcombinations of these, such as are described in reference to FIG. 4hereabove. Additionally, SPU 300 can provide catheter guidance or otherdevice position information, such as is described in reference to FIG. 5hereabove. In some embodiments, SPU 300 can include a electrical signalsource such as a current source that can be coupled to electrodes 141 aand 141 b of diagnostic catheter 100, for example to collect data tocreate a dipole density map and/or to perform distance measurements ashas been described in detail in reference to FIGS. 2A and 2B hereabove.

SPU 300 and/or other components of system 10 can be configured as adistance measurement assembly, such as to produce distance measurementdata as is described in reference to FIGS. 2A and 2B hereabove. System10 can be configured to produce distance measurement data between anytwo or more locations selected from the group consisting of: a locationof a body inserted component or assembly of system 10 such as a locationof a system 10 electrode such as an electrode 141, 241, 541, 641, 741and/or a location of a system 10 ultrasound transducer such as anultrasound transducer 151, 251, 551, 651 or 751; a location of a system10 component that is external to the patient's body such as a surfaceelectrode 820; a location of the patient's anatomy such as a location onthe wall of the left atrium or the left ventricle; and combinations ofthese. In some embodiments, the distance between two splines 131 isdetermined by the distance measurement assembly of system 10. In someembodiments, the distance between a location on a first catheter and alocation on a second catheter is determined by the distance measurementassembly of system 10, such as a location on diagnostic catheter 100 anda location on ablation catheter 200. In some embodiments, the distancemeasurement assembly of system 10 can utilize a determined and/or anapproximated value for the impedance of blood and/or tissue, to performone or more distance measurements. Impedance values used by system 10 inone or more algorithms can vary from patient to patient, and they canvary for one location to another location in a single patient. Impedancevalues can be determined, calibrated or otherwise improved by system 10,such as by performing a distance measurement between two system 10components whose separation distance is fixed or otherwise known anddetermining an impedance value to be used in a subsequent calculation.Multiple impedance values, determined and/or approximated, can beaveraged and the averaged value used in a subsequent calculation.

SPU 300 and/or EDU 400 typically include one or more output devices,such as output devices selected from the group consisting of: a visualdisplay such as a touch-screen display; an audio device such as aspeaker; a tactile devices such as operator worn vibrating bands; andcombinations of these. In some embodiments, information such aselectrical, anatomical and/or device mapping information can be providedto an operator of system 10 via a visual display integral to SPU 300. Insome embodiments, information such as ablation energy deliveryinformation can be provided to an operator of system 10 via a visualdisplay integral to EDU 400.

System 10 can include an accessory device 800, for example an imagingdevice configured to produce an image of the patient's anatomy.Anatomical and other information can be provided by device 800 to SPU300 via cable 804, such that SPU 300 can process the providedinformation in one or more algorithms such as to produce information foran operator, such as electrical, anatomical and/or device mappinginformation. In the embodiment of FIG. 6, accessory device 800 includesultrasound generator 801 which is operably connected to an ultrasoundprobe 802 via cable 803. Anatomical images are produced when probe 802is positioned proximate the patient's skin, such as in combination withan ultrasonic gel known to those of skill in the art. Generator 801 caninclude an output device, such as a visual display to provide a visualimage of the patient's anatomy recorded by device 800. In someembodiments, the visual display is integral to SPU 300 and/or EDU 400.

In some embodiments, generator 801 can communicate with (e.g. send andreceive signals to and from) one or more other ultrasound transducers,such as one or more of ultrasound transducers 151 a, 151 b, 251, 551,651 and/or 751.

Alternatively or additionally, accessory device 800 can comprise arecording device selected from the group consisting of: transesophagealechocardiography device; intracardiac echocardiography device; lassodiagnostic catheter recording device; coronary sinus diagnostic catheterrecording device; and combinations of these.

System 10 can include catheter device 700, typically configured to beslidingly received by shaft 120 of diagnostic catheter 100. Catheterdevice 700 includes handle 710 which is fixedly attached to a flexibleshaft 720. Shaft 720 includes distal end 729. Catheter device 700 caninclude one or more electrodes 741 and one or more ultrasoundtransducers 751, having the same or similar functionality as electrodes141 and ultrasound transducers 151 described in reference to FIG. 1Ahereabove, such as to provide anatomical, electrical and/or devicemapping information to SPU 300 and/or another component of system 10.Electrodes 741 and/or ultrasound transducers 751 can be mounted to shaft720 and/or to an expandable assembly, not shown but as has beendescribed hereabove. Handle 710 can include one or more controls such ascontrol 715. Control 715 can be constructed and arranged to allow anoperator to perform an action selected from the group consisting of:steer shaft 720; control an electrical connection to electrode 741and/or ultrasound transducer 751; and combinations of these. Control 715can be operably connected to a mechanism within handle 710, mechanismnot shown but typically a mechanism selected from the group consistingof: a control cable motion assembly such as a control cable motionassembly connected to a steering pull wire as described herein; a linearmotion assembly constructed and arranged to advance and/or retract acontrol rod; an electric switch; and combinations of these. In someembodiments, catheter device 700 comprises a catheter selected from thegroup consisting of: a catheter with helical array of electrodes such asa lasso catheter; a pacing catheter; an energy delivery catheter such asa catheter constructed and arranged to deliver radiofrequency energy,microwave energy, cryogenic energy, laser energy and/or ultrasoundenergy; a drug or other agent delivery catheter such as a catheterconstructed and arranged to deliver antiarrhythmic medications, stemcells, or other biologic agents; a mechanical device delivery cathetersuch as a catheter constructed and arranged to deploy (e.g. out ofdistal end 729 of shaft 720) a robotic navigation or manipulationdevice, an atrial appendage closure device, a valve replacement device,a tissue biopsy device, or other diagnostic or therapeutic devicedelivered through a lumen of shaft 710; and combinations of these.

System 10 can include robotic control assembly 850, such as a robot orother assembly configured to control one or more linkages, cables orother robotic control mechanisms. Robotic control assembly 850 includescontrol conduit 859 which can be operably attached to one or morerobotically manipulatable assemblies of system 10. As shown in FIG. 6,control conduit can be operably attached to one or more of: diagnosticcatheter 100 via cable 851 ablation catheter 200 via cable 852; seconddiagnostic catheter 500 via cable 853; second ablation catheter 600 viacable 854; and catheter device 700 via cable 855. Each catheter deviceof system 10 can include one or more robotically manipulatableassemblies such as a steering mechanism and/or a catheter shaftadvancing and/or retracting mechanism. In some embodiments, roboticcontrol assembly 850 is used to steer, advance and/or retract diagnosticcatheter 100 and/or ablation catheter 200. Robotic control assembly 850can be used to manually (e.g. operator driven), semi-automatically (e.g.operator driven and system 10 driven) or automatically (e.g. fullydriven by system 10) navigate one or more catheter devices of system 10.System 10 can be configured to receive operator (e.g. clinician) inputinformation, such as clinician input information used tosemi-automatically or automatically navigate one or more catheterdevices of system 10.

Robotic control assembly 850 can navigate one or more devices orassemblies based on an analysis of one or more of: dipole mappinginformation recorded by at least one dipole mapping electrode anddistance information recorded by at least one ultrasound transducer.Robotic control assembly 850 can navigate one or more devices orassemblies based on a distance measurement performed between a firstelectrode and second electrode of system 10, such as has been describedin reference to FIGS. 2A an 2B hereabove.

In some embodiments, manual or automatic navigation can be based upon orotherwise include an assessment of contact of a portion of system 10with tissue. Contact of a portion of system 10 with tissue can bedetermined by analyzing distance signals received by one or moreultrasound transducers of system 10, such as ultrasound transducers 151a, 151 b, 251, 551, 651 and/or 751. Determination of sufficient contactmay be compared to a threshold (e.g. a distance or pressure threshold),such as a threshold that is adjustable by a clinician operator of system10 (e.g. a threshold included in clinician input information).

Referring now to FIG. 7A, a perspective view of a distal portion of adiagnostic catheter is illustrated, including guide elements fordirecting a catheter. Diagnostic catheter 100 of FIG. 7A includes shaft120, lumen 126, expandable assembly 130 including splines 131, andopening 135, each typically of similar construction and arrangement asis described to the similar components of catheter 100 of FIG. 1A.Diagnostic catheter 100 is typically part of system 10, including sheath50 through which shaft 120 has been inserted. Diagnostic catheter 100further includes guide elements 136. Guide elements 136 can comprise twoor more flexible or rigid filaments (e.g. nickel titanium alloyfilaments) configured to provide a biasing force upon a shaft of asecond catheter inserted within shaft 120 of catheter 100. The biasingforce can be configured cause a distal portion of shaft 120 to tend toremain relatively straight and geometrically centered within expandableassembly 130. The biasing force can be used to direct ablation element261 and the distal portion of shaft 220 to pass through opening 135, asshown in FIG. 1A. Once advanced distal to opening 135, ablation element261 can positioned to contact and/or deliver energy to tissue such asheart wall tissue.

In some embodiments, guide elements 136 are constructed and arranged toallow the distal end of an inserted catheter to be steered to passbetween two guide elements 136 (e.g. by overcoming any biasing forceapplied by guide elements 136), and avoid passing through opening 135.Referring now to FIG. 7B, the distal portion 225 of shaft 220 ofablation catheter 200 has been steered to pass between two guideelements 136. Shaft 220 has been further advanced and/or steered to alsopass between two splines 131 as shown, without passing through opening135. Once advanced radially out from splines 131, ablation element 261can be positioned to contact and/or deliver energy to tissue such asheart wall tissue. Numerous forms of guiding elements can be included toallow both a biased linear advancement of an inserted shaft as well as acurvilinear exit pathway between two guiding elements 136 and twosplines 131. Guide elements 136 can be spaced or otherwise constructedand arranged such as to allow or prevent the distal portion of ablationcatheter 200 to exit the expandable assembly 130 prior to passingthrough opening 135.

In some embodiments, guide elements 136 are each fixed on their proximaland distal ends to expandable assembly 130 as shown. In theseembodiments, guide elements 136 can comprise an elastic materialallowing each to stretch, such as to accommodate the expansion andcontraction of assembly 130. Additionally, the elasticity of one or moreguide elements 136 can be configured to bias expandable assembly 130 ina radially expanded state. Alternatively, guide elements 136 can berigid, such as when their proximal ends are slidingly received by shaft120, such as via one or more lumens 126 or finite length channels, notshown but of sufficient diameter and length to allow guide elements 136to slide therein as expandable assembly 130 expands and collapses (i.e.un-expands or compacts). In alternative embodiments, guide elements 136comprise a single tube construction, not shown but a hollow tubeconfigured to guide a catheter or other elongate device to exit shaft120 of diagnostic catheter 100 and pass through opening 135.

While the foregoing has described what are considered to be the bestmode and/or other preferred embodiments, it is understood that variousmodifications can be made therein and that the invention or inventionscan be implemented in various forms and embodiments, and that they canbe applied in numerous applications, only some of which have beendescribed herein. It is intended by the following claims to claim thatwhich is literally described and all equivalents thereto, including allmodifications and variations that fall within the scope of each claim.

1. (canceled)
 2. A catheter system, comprising: a diagnostic cathetercomprising: an elongate shaft comprising a distal end; an expandableassembly mounted to the elongate shaft, the expandable assemblycomprising multiple splines and configured to transition from acompacted state to an expanded state; a plurality of electrodes coupledto the multiple splines of the expandable assembly, each electrodeconfigured to emit electric signals and record electric signals; and aplurality of ultrasound transducers coupled to the multiple splines ofthe expandable assembly; a distance measurement assembly configured todrive the plurality of ultrasound transducers to produce anatomicalgeometry data, and including data representing a distance between eachultrasound transducer of the plurality of ultrasound transducers and atissue surface orthogonal to each ultrasound transducer; and aprocessing unit configured to: measure spacing between two or more ofthe electrodes based on the recorded electric signals and to determine ageometric configuration of one or more of the multiple splines based onthe measured electrode spacing; and create a three-dimensionalanatomical map based on the produced anatomical geometry data, createelectrical information based on the recorded electric signals, anddisplay the electrical information in relation to the three-dimensionalanatomical map, wherein at least one of: the electrical information isfurther based on the determined geometric configuration of the one ormore of the multiple splines, and/or the anatomical geometry data isbased on the determined geometric configuration of the one or more ofthe multiple splines.
 3. The catheter system according to claim 2,wherein: the electrical information is based on the recorded electricsignals and the determined geometric configuration of the one or more ofthe multiple splines, and the anatomical geometry data is based on thedetermined geometric configuration of the one or more of the multiplesplines.
 4. The catheter system according to claim 2, wherein theprocessing unit is further configured to determine a geometricconfiguration of the multiple splines based on the measured electrodespacing.
 5. The catheter system according to claim 2, wherein theelectrical information displayed comprises information selected from thegroup consisting of: cardiac or other tissue voltage measurements;cardiac or other tissue bipolar and/or unipolar electrograms; cardiac orother tissue surface charge data; cardiac or other tissue dipole densitydata; cardiac or other tissue monophasic action potentials; andcombinations thereof.
 6. The catheter system according to claim 2,wherein the processing unit is further configured to derive the shape ofone or more of the multiple splines.
 7. The catheter system according toclaim 6, wherein the processing unit is further configured to derive theshape of the one or more of the multiple splines in real time.
 8. Thecatheter system according to claim 2, wherein the processing unit isfurther configured to derive the relative positioning of two or more ofthe multiple splines.
 9. The catheter system according to claim 8,wherein the processing unit is further configured to derive the relativepositioning of the two or more of the multiple splines in real time. 10.The catheter system according to claim 2, wherein the multiple splinesare resiliently biased in an equilibrium state, and wherein theprocessing unit is further configured to determine a change in the shapeof the multiple splines from the equilibrium state.
 11. The cathetersystem according to claim 10, wherein the change in shape comprises achange in the shape of a single spline.
 12. The catheter systemaccording to claim 10, wherein the multiple splines comprises a firstspline and a second spline, and wherein the change in shape comprises achange in the position of the first spline relative to the secondspline.
 13. The catheter system according to claim 10, wherein: theplurality of electrodes comprises a first electrode and a secondelectrode, the change in shape comprises a bowing of a first spline, thefirst electrode and the second electrode are attached to the firstspline, and the bowing causes the spacing between the first electrodeand the second electrode to decrease.
 14. The catheter system accordingto claim 10, wherein: the plurality of electrodes comprises a firstelectrode and a second electrode, the change in shape comprises astraightening of a first spline, wherein the first electrode and thesecond electrode are attached to the first spline, and the straighteningcauses the spacing between the first electrode and the second electrodeto increase.
 15. The catheter system according to claim 2, wherein: theplurality of electrodes comprises a first electrode and a secondelectrode, and the system applies a current between the first electrodeand the second electrode to determine the spacing between the firstelectrode and the second electrode.
 16. The catheter system according toclaim 2, further comprising an ablation catheter comprising: an elongateshaft with a distal portion; and at least one ablation elementpositioned on the distal portion and configured to deliver energy totissue.
 17. The catheter system according to claim 16, wherein the atleast one ablation element comprises an ablation element selected fromthe group consisting of: an electrode; a vessel configured to delivercryogenic energy; a laser diode; an optical fiber configured to deliverablative energy; a microwave energy delivery element; an ultrasoundenergy delivery element; a drug or other agent delivery element; andcombinations thereof.
 18. The catheter system according to claim 2,further comprising a sheath with a distal end, and wherein theexpandable assembly is configured to radially expand as it exits thesheath distal end.
 19. The catheter system according to claim 2, whereinthe plurality of electrodes comprises at least one electrode with animpedance of less than 10,000 ohms for frequencies above 0.1 Hertz. 20.The catheter system according to claim 2, wherein the plurality ofultrasound transducer comprises an assembly selected from the groupconsisting of: single or multi-element piezoelectric ceramics;piezoelectric micro-machined ultrasound transducers (pMUT); capacitivemicro-machined ultrasound transducers (cMUT); piezoelectric polymers;and combinations thereof.
 21. The catheter system according to claim 2,wherein each of the plurality of ultrasound transducers is disposedbetween two electrodes.
 22. The catheter system according to claim 2,further comprising at least one body surface electrode, wherein thedistance measurement assembly is further configured to deliver a signalto the at least one body surface electrode, record a second generatedsignal from the at least one body surface electrode, and produce asecond set of distance information based on the recording of the secondgenerated signal.
 23. The catheter system according to claim 2, whereinthe three-dimensional anatomical map includes at least one of heart wallposition information or heart wall thickness information.